1. Field
The present disclosure relates to a heat dissipation structure of an electronic device, and more particularly to a heat dissipation structure of a server device for heat dissipation using a cooling fluid.
2. Related Art
At present, a heat dissipation module used for a central processing unit (CPU) of a server generally employs a heat sink structure. The principle is using a large contact area between the heat sink and the air, and using heat convection to help the heat dissipation of the CPU. However, the heat dissipation problem of other electronic elements is relatively caused while the heat sink dissipates the heat of CPU.
For example, when airflow flows through the CPU and removes the heat energy generated by the CPU, the temperature of the airflow is raised, and such high-temperature airflow is adverse to the heat dissipation of other electronic elements. Therefore, in order to overcome the problem above, the flow rate of the airflow needs to be enhanced, that is, the power of an air supply device for heat dissipation needs to be improved to enhance the air exhaust rate. However, the system load is caused to be relatively increased if the power of the air supply device for heat dissipation is improved. Moreover, the smaller volume of the server results in the smaller inner spacing for circulating of the airflow, and thus the heat dissipation effect using heat convection becomes much poorer. However, as required by information explosion, the circuit integration degree of a circuit board in a server will necessarily be increased in order to improve the operation efficiency of the server to a higher level. Therefore, the space in the server will be filled with more electronic elements and becomes congested, and thus excessive accumulation of the heat energy is caused. In view of this, the cooling or temperature drop manners of the server must be further improved, so as to meet the heat dissipation demand of high heat energy generated by a server due to high operation efficiency.
In order to overcome the problems above, the improvement of the heat dissipation mode of the heat pipe is necessary. As design theory of a heat pipe for transferring heat is not cooling or lowering the temperature by using air, the space for flowing of airflow does not need to be considered. Therefore, the volume of a server can be designed to be much smaller, and the system air pressure drop may also be reduced, so as to solve the problem of energy consumption.
For example, in U.S. Pat. No. 6,388,882 (referred to as '882 hereinafter), an evaporation end of a heat pipe is disposed on a CPU of a main board, so as to enable the evaporation end to transfer the heat energy to a condensation end of the heat pipe. When the main board is disposed in a rack of the server, the condensation end of the heat pipe contacts with a cooler disposed on the server cabinet, and the cooler dissipates the heat energy on the condensation end.
However, the condensation end of the heat pipe in '882 is engaged in a groove in the cooler to contact the heat pipe with the cooler. Furthermore, heat conduction effect is achieved between the condensation end and the cooler in a solid-solid contact manner. However, in order ensure the efficiency of heat conduction, the condensation end and the groove in the cooler must be made of materials having a high thermal conductivity, for example, metal material such as copper. As a result, the condensation end and the cooler are combined in a rigid body to rigid body contact. That is to say, heat conduction is generated between the condensation end and the cooler using surface contact of rigid body to rigid body, thereby removing the heat energy. Therefore, when the condensation end is mated with the cooler, if a gap therebetween is too large, the heat dissipation effect is easily caused to be poor due to the incomplete contact between the condensation end and the cooler. Alternatively, if the mating gap between the condensation end and the cooler is too small, interference and collision with each other easily occur, thereby causing the damage.